The length of a typical action-movie gunfight is realistic.

busted

The Build Team chose four fully automatic weapons for testing: MAC-10 and Uzi machine pistols, and AK-47 and M16 rifles. It took them 2 seconds to fire a full magazine from each weapon. For the MAC-10 and Uzi, it took 10 seconds to empty two magazines; Grant needed a total of 27 seconds to fire four magazines from the Uzi. The team remarked that the short firing times made the movie firefights ridiculously long unless the participants had access to vast stores of ammunition.

A person firing two pistols simultaneously, rather than alternating left/right hand shots, can hit targets more effectively than a person holding one pistol in a two-handed stance. (A revisit of Firearm Fashion.)

confirmed

Adam and Jamie fired a pair of pistols with 8-round magazines, using a 10-point scale based on speed and accuracy as in the 2011 test. They averaged 8.1 against a single target, 7.4 against two separate targets. Both of these results were higher than the 7.3 average from a control run using a single pistol in a two-handed stance.

Bullets can retain lethal speed when fired into several feet of water. (Based on a scene in the film Mission Impossible: Ghost Protocol.)

busted

Adam and Jamie presented footage from Bulletproof Water to demonstrate the manner in which bullets quickly lost speed after being fired into water.

A MAC-10 machine pistol dropped down a flight of stairs can start firing by itself. (Based on a scene in the film True Lies.)

busted

Grant and Tory set up a flight of stairs and a rig to drop a MAC-10 (loaded with blanks) at the top. Two tests with different drop heights failed to cause a discharge; Grant commented that the movie weapon may have been fitted with a hair trigger or other modifications to set it off.

A nail gun can inflict wounds as lethal as a firearm.

busted

For a control run, Tory fired a 9 mm pistol at a target from 14 ft (4.3 m), and achieved a 2.5 in (6.4 cm) grouping with several shots penetrating fully. A test with the nail gun gave similar accuracy, but the nails only bounced off; when he fired from 7 ft (2.1 m), only a few of them penetrated shallowly.

In a gunfight, the person who draws second has a better chance of winning.

busted

The Build Team measured their time to draw and fire a double-action pistol on their own (“action”), then to do the same once a red light came on (“reaction”). Kari and Tory both registered significantly shorter “reaction” than “action” times, so Adam and Jamie set up a trial to factor in the effect of a live enemy shooting back. Armed with paintball pistols and facing off at 10 ft (3.0 m), they carried out six showdowns, with each man firing first in three and second in the other three. In every trial, the man who drew first was also first to fire, but most of them were nearly simultaneous. They noted that two equally matched gunfighters would probably end up killing each other.

Bullets made of silver or engraved with an enemy’s name can be as effective as unmodified ammunition.

busted (silver) /confirmed(engraved)

The Build Team brought in a firearms expert to fire an M1 Garand rifle at a target 100 ft (30 m) away, backed with clay blocks behind the center of mass to determine penetrating power. A control run with standard lead bullets gave high accuracy and easily punched through the clay. Three shots with silver bullets struck far off center, while the engraved rounds performed as well as the lead ones. Kari noted that because silver tends to shrink and deform as it cools after molding, those bullets may have acquired shape irregularities that affected their flight.

Someone who is running through gunfire will never be hit.

busted

The Build Team set up an obstacle course for Tory to run through while Grant and Kari fired paintball guns at him. He lasted 6 seconds before being hit when he ran the course unarmed. During a second trial, in which he was given a gun and could shoot back, he lasted 32 seconds and managed to hit both Grant and Kari in that time.